Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B0158 03: Outside Air Temperature Sensor Circuit Voltage Below ThresholdDTC B0158 07: Outside Air Temperature Sensor Circuit Voltage Above Threshold
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ambient Air Temperature Sensor Signal | B0158 03 | B0158 03 | B0158 07* | B0158 03, 07 |
Low Reference | -- | B0158 07 | B0158 07 | B0158 03, 07 |
Circuit/System Description
The HVAC control module supplies the ambient air temperature sensor with a low reference circuit and 5-volt signal circuit. The HVAC control module determines the voltage drop across the sensor, which is proportional to temperature. As the air temperature increases, the sensor resistance decreases and the voltage signal decreases. As the air temperature decreases, the sensor resistance increases and the voltage signal increases.
Conditions for Running the DTC
The ignition is turned ON.
Conditions for Setting the DTC
The HVAC control module detects the ambient air temperature sensor signal circuit is less than -36°C (-38°F) or more than 215°C (419°F) for more than 15 seconds.
Action Taken When the DTC Sets
| • | The HVAC control module will display dashes for outside air temperature. |
| • | The DIC will display SERVICE A/C SYSTEM. |
| • | The system operates using a default value. |
Conditions for Clearing the DTC
| • | The DTC will become history if the HVAC control module no longer detects the condition that set the DTC. |
| • | The history DTC will clear after 50 fault-free ignition cycles. |
Diagnostic Aids
If the outside (ambient) air temperature sensor has an out of range condition caused by a short to voltage, short to ground or open/high resistance the scan tool will display the last normal operating range.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Manual HVAC Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the outside air temperature sensor.
- Ignition OFF, test for less than 1 ohm between the low reference circuit B and ground.
- Ignition ON, test for 5 volts between the low reference circuit terminal B and the 5-volt reference signal circuit terminal A.
- If all circuits test normal, test or replace the outside air temperature sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC control module. |
| ⇒ | If not the specified voltage, test the signal circuit for a short to voltage, short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC control module replacement, setup and programming |
